HomeMy WebLinkAboutFire Report_RedactedAuthorization
62800 MacDonald, John 10/20/2025
Officer In Charge ID Signature Position or Rank Assignment Date
46955 Hoover, Nicholas Fire Captain Fire Station 4 10/20/2025
Member Making Report ID Signature Position or Rank Assignment Date
M
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NFIRS-10 Personnel
40060 CA 10 20 2025 Fire Station 4
(FS4)
25-06249 0
FDID State Month Day Year Station Number E posure
A
Page 7 of 12
NFIRS-1S Supplemental
40060 CA 10 20 2025 Fire Station 4
(FS4)
25-06249 0
FDID State Month Day Year Station Number Exposure
Primary Narrative:
BC 2 with a first alarm was dispatched to a structure fire originally reported at the PG&E yard on South Higuera. On the
arrival of E4, they determined that the fire was in the RV storage facility next door. E4 and the first alarm assignment were
redirected to that location. BC 2 arrived and established Vachell IC. Vachell IC reduced the assignment to E3, E4, and T1. E4
conducted fire attack and exposure protection. E3 and T1 assisted with the water supply and personnel. Vachell IC requested an
investigator and made contact with the property owner.
Once the fire was contained overhaul was conducted, and T1 and E3 were released. E4 remained on scene until the investigator
arrived. Vachell IC remained on scene with the investigator and then turned the scene over to him.
Vachell IC was terminated. BC 2 cleared.
See supplemental reports for findings of the investigation.
Additional Narrative (#1 of 3):
T1 arrived and was assigned to assist E4 with manpower. T1 opened up the front of the trailer to check for extension and
overhauled the front bedroom area including battery, propane tanks, small gasoline can, and personal items. T1 found no additional
fire or significant heat. T1 was released by B2 and cleared the scene without further incident.
Additional Narrative (#2 of 3):
E4 arrived at the initial reported location and determined the fire was at the neighboring property, E4 reported best access
via radio and redirected to the RV storage yard entrance. Upon arrival, E4 located a single travel trailer well involved with fire,
directly exposing two portable propane tanks and the neighboring two fifth wheel trailers. FF4 used the front bumper line to knock
the fire down. E4 assisted with overhaul, removed the propane tanks and gasoline tanks, and monitored the area for any hidden
fire. No further fire was seen, thermal imaging camera did not reveal any hidden heat, scene was turned over to BC2 and E4
became available without further incident.
A
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Additional Narrative (#3 of 3):
SLO FD FIRE ORIGIN & CAUSE INVESTIGATION REPORT
DATE:10/20/2025, 0637 Hours
LOCATION: 4353 Vachell Ln, San Luis Obispo, CA 93401
PROPERTY TYPE: Commercial Yard
CLASSIFICATION: Accidental
INCIDENT #: SLO-FD 25-06249
REPORTING OFFICER: DANIEL, JOSHUA Fire Marshal (PREV 20)
SYNOPSIS
This report documents the investigation into the origin and cause of a vehicle fire.
SOURCE OF ACTIVITY
On October 20, 2025, at approximately 0630, San Luis Obispo County Dispatch received a 911 emergency call reporting a Fire at
4353 Vachell LN, San Luis Obispo, CA. 93401 in San Luis Obispo County.
At approximately 0637 hours, while working my regular schedule as the SLO Fire Department (SLOFD) Fire Marshal (PREV20), I
responded code two from my office at SLOFD Station 1, 2160 Santa Barbara Ave., San Luis Obispo, CA. I arrived at the fire scene at
approximately 0730 hours and cleared it at approximately 0930 hours.
OBSERVATIONS/ACTIONS
Upon my arrival, I observed BC2 waiting for the arrival of a Fire Investigator.
INVESTIGATION
My investigation actions and findings are based on a scientific examination of the origin and cause of the fire.
Methodology
The methodology I utilized during this investigation consisted of identifying all available data for origin determination, including
witness accounts, an initial scene assessment, development of a preliminary fire spread hypothesis, an in-depth examination of the
fire scene, reconstruction of the fire scene, development of a final fire spread hypothesis, and identification of the fire’s origin.
I identified all available data for cause determination, including ignition sources, fuel packages, oxidizers, and circumstances. I
utilized all available resources to develop fire-cause hypotheses and determine which hypotheses best fit the credible data
available to identify the cause of this fire.
During my investigation, I obtained witness statements. I conducted the interviews in full uniform. The following is a summary of
the statements I collected.
Summary of Statements
is registered owner of the RV and stated he dropped the RV off on 10/19/2025 at 1635 after using the RV all
weekend long on a camping trip. The RV is a 2012, 27-foot Lance 2285 Travel Trailer License plate . Per his insurance
carrier is Progressive, and his policy is active. reports no issues mechanically or electrically with the trailer. He also stated
having done no work or upgrades to the trailer outside of general maintenance and repairs.
END OF STATEMENT
Systematic Approach
I began my investigation by systematically and methodically walking through the fire scene, from exterior to interior, identifying all
available data to determine where and how the fire started.
I walked through the exterior in a clockwise fashion, noting significant fire damage to the front side of the trailer. The fire crew
started cutting a hole in the front side of the trailer to make entry and to engage in fire suppression activities.
Area of Origin (AOO)
After careful consideration that all credible data has been accounted for and all credible alternate origin hypotheses have been
considered and eliminated, it is my opinion that the area of origin was the external battery area of the trailer. Located on the tow
bar of the trailer was mounted in a cover a RV rated battery. Next to the battery mount was two external propane tanks also
mounted to the tow bar. The wiring from the battery to the disconnect switch was intact and the insulation melted away.
AOO Fire patterns showed the fire started on the external side of the travel trailer and used the flammable materials that made up
the front wall components and the spare tire to burn into the internally.
AOO Competent Ignition Sources
All AOO Competent Ignition sources were electrical in nature. It is unknown if the battery was the primary cause or if the wires
failed.
FIRE CAUSE
1. IGNITION SOURCE: Electrical
2. MATERIAL FIRST IGNITED: Flammable building materials
3. OXIDANT: Oxygen from surrounding air
4. EVENT WHICH BROUGHT IGNITION SOURCE AND MATERIAL FIRST IGNITED TOGETHER: The electrical components (battery and
wiring) of the trailer failed and ignited the surrounding materials on fire.
PHOTOS
# 79 DIGITAL PHOTOGRAPHS WERE TAKEN AND UPLOADED TO THE ELECTRONIC CASE FOLDER
# 0 VIDEOS WERE RECORDED AND UPLOADED TO THE ELECTRONIC CASE FOLDER
EXPOSURES
1. ACTUAL EXPOSURES: Two 5th wheel type trailers were located on each side of the trailer that was no involved in the fire. But
one trailer showed signs of damage from the radiant heat.
2. POTENTIAL EXPOSURES: The entire row of RV trailers potentially could have burned.
CONCLUSION Page 11 of 12
I believe the fire was caused by the electrical components on the travel trailer. There by igniting the flammable materials around
the ignition source.
CLASSIFICATION OF THE CAUSE
ACCIDENTAL: The proven cause does not involve an intentional human act (2017 NFPA 921 20.1.1)
My opinion of the origin and cause of this fire is based on the following:
1. My more than (10) years of professional service in the firefighting industry
2. My more than (8) years of professional full-time fire investigations
3. I have personally conducted and/or assisted in over (250) fire events
4. I have over (300) hours of fire investigation and related law enforcement training
END OF INCIDENT REPORT
Apparatus Narrative for BC2:
Unknown
Apparatus Narrative for E3:
Unknown
Apparatus Narrative for T2:
Unknown
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